OSL and 14 C chronologies of a H olocene sedimentary record ( G arding‐2 core) from the G erman N orth S ea coast

• Published in: Boreas 2014-10, Vol.43 (4), p.856-868
• Main Authors: Zhang, Jingran, Tsukamoto, Sumiko, Grube, Alf, Frechen, Manfred
• Format: Article
• Language: English
• ISSN: 0300-9483; 1502-3885
• DOI: 10.1111/bor.12071

The history of sea‐level change and sediment accumulation since the last deglaciation along the G erman N orth S ea coast is still controversial because of a limitation in the quantity and quality of chronological data. In the current study, the chronology of a 16‐ka coastal sedimentary record from the G arding‐2 core, retrieved from the E iderstedt P eninsula in S chleswig‐ H olstein, northern G ermany, was established using OSL and AMS 14 C dating techniques. The robust chronology using 14 radiocarbon and 25 OSL dates from the G arding‐2 core is the first long‐term record that covers the H olocene as well as the last deglaciation period in one succession in the G erman N orth S ea area. It provides a new insight into understanding the H olocene transgression and coastal accumulation histories. The combined evidence from the sedimentology and chronology investigations indicates that an estuarine environment dominated in E iderstedt P eninsula from 16 to 13 ka, followed by a depositional hiatus between 13 and 8.3 ka, attributed to erosion caused by the H olocene transgression; the onset of the H olocene transgression at the core site occurred at around 8.3 ka. The sea level continued to rise with a decelerated rate until around 3 ka. Since 3 ka, the shoreline has begun to prograde. Foreshore (tidal flat) sediments have been deposited at the drilling site with a very high sedimentation rate of about 10 m ka −1 . At around 2 ka, a sandy beach deposit accumulated in the sedimentary succession, indicating that the coastline shifted landward, which may represent a small‐scale transgression in the late H olocene. At around 1.5 ka, terrestrial clastic sediment started to accumulate, indicating a retreat of the relative sea level in this area, which may be related to local diking activities undertaken since the 11th century.